1. Field of the Invention
Embodiments described herein relate generally relate to a sanitary washing apparatus.
2. Background Art
Sanitary washing apparatuses can clean the human private parts by washing with water. Hence, sanitary washing apparatuses are rapidly becoming popular.
In this context, a sanitary washing apparatus including a pressure generating section for causing a pulsating transition is proposed. In the pulsating transition, a pressure higher than the jetting pressure obtained from the supply water source is intermittently generated so as to achieve a comfortable feeling of washing even with a reduced amount of water used (see Japanese Patent No. 3264274).
This sanitary washing apparatus disclosed in Japanese Patent No. 3264274 can jet water with increased velocity and repeatedly pulsating flow by causing the pulsating transition of pressure.
Thus, after jetting, water portions with different velocities unite into a large jetting water group, which can be caused to impinge on the human private parts. More specifically, a water portion with fast velocity overtakes a water portion jetted earlier with slow velocity to form a large jetting water group. Although jetted in a small amount of water, a large jetting water group has been formed at the time of impingement on the human private parts. Thus, the disclosed technique is superior in being able to provide a comfortable feeling of washing even with a small amount of water.
However, the technique disclosed in Japanese Patent No. 3264274 has a problem of tradeoff between the feeling of stimulation (the feeling of being strongly washed by water with fast velocity) and the feeling of volume (the feeling of being washed by a large amount of water). Specifically, because velocity difference between jetting water portions is used to form a large jetting water group, the velocity of jetting water decreases. Hence, although the feeling of volume increases, the feeling of stimulation decreases. Conversely, if the feeling of stimulation is increased, the feeling of volume decreases. Thus, further improvement is desired to provide a greater feeling of washing. The inventors have been dedicated to research and development to provide a greater feeling of washing by a smaller amount of water.
On the other hand, the inventors have investigated such techniques as in JP-A 2002-155567 (Kokai) to realize a great feeling of washing with compatibility between the feeling of volume and the feeling of stimulation.
JP-A 2002-155567 (Kokai) discloses a sanitary washing apparatus in which water is squirted from an orifice section straight toward a jetting port, passes through an air intake section, and is jetted from the jetting port (see [Claim 1], paragraphs [0006] to [0014], FIG. 2, etc. in JP-A 2002-155567 (Kokai)).
In this sanitary washing apparatus disclosed in JP-A 2002-155567 (Kokai), the surface of continuously jetted water is disturbed by the air taken in by the jet flow due to the air intake effect (ejector effect) to form a thin portion and a thick portion in the water. In the portion where the water is thicker, in other words, where the water is denser, the jetting water causes the feeling of volume when impinging on the human private parts. Furthermore, because the water is squirted straight toward the jetting port from the orifice section for causing the ejector effect, it is possible to reduce energy loss due to collision of water with the nozzle inner wall surface, i.e., to suppress the decrease of the feeling of stimulation due to deceleration of water. As compared with conventional sanitary washing apparatuses based on continuous jetting, the technique is superior in being able to provide a great feeling of washing with compatibility between the feeling of volume and the feeling of stimulation.
However, in this technique disclosed in JP-A 2002-155567 (Kokai), a problem is that a large amount of water is required because of the configuration of continuous jetting. In addition, there is another problem with the size increase and cost of the apparatus because of the need of an apparatus for causing the ejector effect. Furthermore, in the configuration of this technique, the feeling of volume is created by generating disturbances in the surface of water by the ejector effect, and the feeling of stimulation is created by suppressing the velocity decrease of water obtained by the supply water pressure. Hence, there is a limit to increasing the contrast between the feeling of volume and the feeling of stimulation. Thus, improvement is desired also from the viewpoint of providing a feeling of washing at high level.
JP-A 2002-155567 (Kokai) also discloses a sanitary washing apparatus in which water is squirted from an orifice section straight toward a jetting port, passes through a resonance chamber, and is jetted from the jetting port (see [Claim 8], paragraphs [0026] to [0027], FIG. 13, etc. in JP-A 2002-155567 (Kokai)).
In this sanitary washing apparatus disclosed in JP-A 2002-155567 (Kokai), when water is squirted from the orifice section, a negative pressure occurs in the resonance chamber. Then, the water is attracted by the negative pressure of the resonance chamber to become jetting water with a conically expanding cross-sectional area. On the other hand, when the negative pressure in the resonance chamber exceeds a certain level, atmospheric air is sucked from the jetting port, and the pressure in the resonance chamber becomes positive. Then, the jetting water is jetted in a linear shape as it is squirted from the orifice section. When the jetting water with a conically expanding cross-sectional area impinges on the human private parts, the feeling of volume is produced. On the other hand, when the linear jetting water impinges on the human private parts, the feeling of stimulation is produced. The jetting water with a conically expanding cross-sectional area and the linear jetting water are alternately repeated. Thus, as compared with conventional sanitary washing apparatuses based on continuous jetting, the technique is superior in being able to provide a great feeling of washing with compatibility between the feeling of volume and the feeling of stimulation.
However, in this technique disclosed in JP-A 2002-155567 (Kokai), a problem is that a large amount of water is required because of the configuration of continuous jetting. Furthermore, in the configuration of this technique, the feeling of volume is created by expanding the cross-sectional area of water by the negative pressure of the resonance chamber, and the feeling of stimulation is created by suppressing the velocity decrease of water obtained by the supply water pressure. Hence, there is a limit to increasing the contrast between the feeling of volume and the feeling of stimulation. Thus, improvement is desired also from the viewpoint of providing a feeling of washing at high level.